In a kinetic roughening process [1]}, the global roughness scales as \(W\sim t^{\beta }\)  — with \(\beta \)  being the so-called growth exponent — up to a saturation value \(W_{sat} \sim L^{\alpha }\)  which is reached at steady state — here, \(\alpha \)  is the so-called roughness exponent, which is related to the fractal dimension \(D_f\)  of the front considered as a self-affine fractal, as \(\alpha =d+1-D_f\)  [1]}. The time \(t_{sat}\)  required for the system to reach the steady state scales as \(t_{sat} \sim t^z\) . Here, \(z=\alpha /\beta \)  is the so-called dynamic exponent, which characterizes the time dependence of the lateral correlation length \(\xi \)  along the front as \(\xi \sim t^{1/z}\)  [1]}. It is possible to define a scaling function \(f_W\)  that summarizes these scaling laws into the single expression
\(W(L,t) \sim L^{\alpha } f_W \left( \frac{t}{L^z} \right),\) 
